mercruiser 3.0 tach

[Glassport from Newport]

My 1991 Bayliner Capri, with a mercruiser 3.0l, is having tachometer issues. I checked the wiring and everything seems to be ok. The tach doesn't read accurately and is slow to move as you move the throttle. It won't read anything under 900 to 1000 rpm. It is the Delco EST ignition and a US Marine tachometer. How do I determine if the gauge needs replacing? If the gauge is ok, where do I go from here? I followed the wiring according to the manual and everything seems to be attached properly. If I do need a new gauge, does anyone have an idea as to how I can match up a new tach with the other gauges? Can I change the face of the gauge to make it match? Thanks in advance for any help.

1991 Bayliner Capri 1850, Mercruiser 3.0l (sn D610831) Alpha One genII (sn OD559854)

 

[Gary H NC]

Re: mercruiser 3.0 tach

Did you clean the connections or just look at them? Big difference.
Also may want to check the ground to the gauges...
Are any other gauges acting strange?

 

[Glassport from Newport]

Re: mercruiser 3.0 tach

All other gauges work fine. I didn't clean anything, I'll try that to see if it helps. I was concerned with the sender wire. Is is possible for the coil to malfunction and cause this, or would it be more likely that the gauge is bad?

 

[Bondo]

Re: mercruiser 3.0 tach

or would it be more likely that the gauge is bad?

Ayuh,... Much more...